The present invention refers to a system for recording an information character record onto a magnetic substrate comprising a first memory for storing a microprogram adapted to control the record operation, a second memory for storing said characters, a central unit being responsive to this microprogram for reading the characters in said second memory and a record device for recording said characters onto said magnetic substrate.
Previously known devices for recording items of information onto magnetic substrates e.g., magnetic cards or magnetic tapes, may use the so-called "Frequency Duplication" record system.
This system consists in recording a timing signal at equal intervals, and the information signal after a time period which is approximately half of said interval. More particularly, if the bit to be recorded has a bit which has the value "1" then an information signal is present; conversely, the absence of this information signal denotes that the character has a bit which has a value "0". Systems of such type generally comprise: a shift register for storing an 8-bit character and adapted to allow the reading of one bit at a time to be recorded; a clock for generating signals marking the timing intervals; and, a frequency duplicator adapted to generate a frequency which is twice the clock frequency so as to allow the record of the information bits in the middle of the timing interval.
Such a system has the disadvantage of requiring specialized wiring for the record operation. Another disadvantage consists in the fact that the system timing must be exactly synchronized with the overall timing of the machine in order to avoid recording errors.
Furthermore, such systems are not economically justifiable in a machine of the microprogrammed central unit type, where, as recited below, the circuit functions may be executed by the central unit.